A Pure Sample of ²²⁶Ra Contains 1

Multiple Choice

A pure sample of ²²⁶Ra contains 1.5 × 10¹³ atoms of the isotope.If the half-life of ²²⁶Ra = 1.6 × 10³ years,what is the decay rate of this sample? (1 Ci = 3.7 × 10¹⁰ decays/s)

A) 8.0E-9 Ci
B) 2.1E+2 Ci
C) 5.6E-9 Ci
D) 1.8E-1 Ci
E) ​2.5E-1 Ci